Ozone is widely used for treating drinking and sewage waters, germicidal treatment of facilities/equipments in food factories and the like, household disinfection, etc., because of its strong oxidative power. It is also used for forming oxide films of wafers in semiconductor industry. However, ozone induces health problems such as headache, vomition and pulmonary edema by its strong oxidative power, so that spent ozone after use should be decomposed and detoxified. Conventional methods for decomposing such ozone involved contacting exhaust gas containing ozone with activated carbon or a metal having ozone-decomposing ability supported on zeolite or the like.
However, activated carbon is often used at intentionally lowered decomposition speed by granulation with other components to prevent the danger of explosion when it is used for decomposition/detoxification of ozone contained at high concentrations in exhaust gas. On the other hand, granular activated carbon is insufficient in removal performance when ozone is contained at low concentrations in exhaust gas.
An alternative means using activated carbon fiber was proposed. Activated carbon fiber is effective even for decomposition/removal of low concentrations of ozone because of its large surface area and high decomposition speed. It also has the advantage that it can be easily formed into a shape of a filter or the like. However, ozone-scavenging materials based on activated carbon fiber have problems such as high cost and dust.